Demerits of Government Companies:

1. Lack of Autonomy: Government companies do not enjoy complete autonomy to take decisions. This often leads to delays and inefficiencies.

2. Bureaucratic Interference: Government companies have to deal with bureaucratic interference from government officials, which can hinder their operations.

3. Inefficiency: Government companies often suffer from inefficiencies due to bureaucratic red tape and lack of competition.

4. Lack of Accountability: Government companies are not subject to the same level of accountability as private companies. This can lead to mismanagement and corruption.

5. Political Interference: Government companies are often subject to political interference, which can lead to decisions being made for political rather than economic reasons.

Features of Government Companies:

1. Government Ownership: Government companies are owned and controlled by the government.

2. Legal Status: Government companies have a separate legal status from their owners, which allows them to enter into contracts, sue and be sued.

3. Public Purpose: Government companies are established to serve a public purpose, such as providing essential services or promoting economic development.

4. Limited Liability: Government companies have limited liability, which means that shareholders are not personally liable for the company's debts.

Merits of Government Companies:

1. Public Interest: Government companies are established to serve a public purpose, which ensures that their operations are in the public interest.

2. Stability: Government companies are often more stable than private companies, as they are not subject to the same fluctuations in the market.

3. Strategic Importance: Government companies often operate in strategic sectors, such as energy or telecommunications, which are essential to the country's economic development.

4. Social Responsibility: Government companies are often more socially responsible than private companies, as they are accountable to the government and the public.

Changing Role of Public Sector:

1. Privatization: The public sector is increasingly being privatized, as governments seek to reduce their role in the economy.

2. Public-Private Partnerships: Governments are increasingly partnering with private companies to provide public services, in order to reduce costs and improve efficiency.

3. Deregulation: Governments are deregulating industries, in order to promote competition and increase efficiency.

4. Focus on Efficiency: The public sector is increasingly focusing on efficiency, in order to reduce costs and improve services.

In conclusion, while government companies have some advantages, such as serving the public interest and being more socially responsible, they also suffer from inefficiencies, bureaucratic interference, and lack of autonomy. The changing role of the public sector is leading to more privatization, public-private partnerships, deregulation, and a focus on efficiency.